In a large bowl, cream together butter and sugars until creamy. Add egg and vanilla and mix until smooth.
In a separate bowl, sift together dry ingredients and gradually add to the wet ingredients, a third at a time. Mix until the dough starts to come together.
Cover and refrigerate for 30-40 minutes.
Take half the dough and turn out onto a clean and well-floured surface.
Roll dough out to be ¼ inch thick. Use a large round cookie cutter to cut out circles. Place cutouts on a baking sheet lined with parchment paper.
Bake for 8-9 minutes at 375.
When cookies are done, let sit for 1-2 minutes before moving to a cooling rack. Allow to cool completely before frosting and decorating.